Q: I have a old MacBook (2011) while typing it highlights as if it will be deleted and then freezes so I can't click to get out of that mode.  Also my cursor seems out of control.

Does this occur in a browser, if so which browser?

If this is the case, there may adware or other issue involved.

Adware Removal Guide:

http://www.thesafemac.com/arg/

This covers an issue where underlined words and odd things can happen:

http://www.reedcorner.net/eliminating-browser-redirects-and-advertisements/

Sometimes, a browser extension or other accidental download

of a disruptive factor can play havoc; usually not in another app

than the browser. This is vaguely referred to as adware.

• Stop pop-up ads and adware in Safari - Apple Support

If the issue occurs with the internet turned off and in a non-internet

application, or in a second user account than the first one that had

exhibited the problem, then it may be seen as system wide. At that

point the problem may be hardware. The keyboard and trackpad

can have issues, if the internal battery has expanded enough to push

up on the inside of the case and affect keyboard functions.

The computer could be inspected and suggestions made as to what

else to try, if you contact an Apple Store to set an appointment for a

genius person to look into it. Or see about taking the unit to an Apple

authorized service provider to have the hardware tested.

• Make an appointment at an Apple Retail Store Genius Bar
• Find an Apple Authorized Service Provider

Troubleshooting this at home includes checking for adware or other

malcontents that a browser may acquire while online; you could see

how Etrecheck can generate a report and offer suggestion on how to

deal with certain symptoms clues in report: http://etrecheck.com/#about

Not sure which of the afflictions your Mac may have acquired, or when

the symptoms appear; since you don't specify. The above may help.

Good luck & happy computing!